Refrigeration



Feb. 27, 1940. H. M. 'ULLS'1'RAND REFRIGERATION Filed April 7, 1938 35INVENTOR.

Qefaaa AATTORNEY.

Patented Feb. 27, 1940 UNITED STATES PATENT OFFICE REFRIGERATIONDelaware Application April '7, 1938, Serial No. 200,572

4 Claims.

My invention relates to an absorption refrigeration system and it is anobject of the invention to provide such a system having greaterefficiency.

The single figure of the drawing shows more or less diagrammatically anabsorption refrigeration system of a type making use of auxiliarypressure equalizing fluid.

A generator ID has a horizontal portion divided into three chambers l2,and |3. Chamber II is provided with a standpipe 4. Chamber I3 isprovided with a standpipe |5. Chamber I2 is provided with a dome IS. Athermosyphon or vapor liquid lift conduit I1 is connected from chamberl2 to the upper part of standpipe l4. The lower end of conduit I1projects downward through dome l6 into chamber I2. Chambers I2 and I3communicate with each other through a small opening |3. The generator isheated by a gas burner l9 arranged so that the flame is projected intothe endbf a flue 20 which extends through the horizontal portion of thegen erator.

An absorber 2| is provided with a cooling coil 22. Coil 22 may beconnected to an air cooled condenser, not shown, forming therewith avaporization-condensation circuit for cooling of the absorber. Theabsorber may also be water cooled or direct air cooled.

A condenser 23 comprises a pipe coil provided with heat transfer fins 24fordirect air cooling.

An evaporator 25 comprises a pipe coil locatedin an insulatedrefrigerator storage compartment 26.

The evaporator 25 and absorber 2| are interconnected for circulation ofgas therethrough and therebetween-by members including a gas heatexchanger 21. The lower end of condenser 23 is connected by a conduit 23to the upper end of evaporator 25. Conduit 23 conducts liquid from thecondenser to the upper part of the evaporator.

The lower end of condenser 23 is also connected to theevaporator-absorber. gas circuit by a conduit 29, gas storage vessel 3l,and conduit 3|. Vessel is usually referred to as a pressure vessel.

The generator 14 and absorber 2| are interconnected for circulationtherethrough and therebetween of liquid by members including a tripleheat exchanger 32. This triple heat exchanger may be formed as shown bythree con-- centric tubes providing an outside passage 33, a middlepassage 34, and an inner passage 35. Generator chamber H is connected bya conduit 36 to one end of inner passage of the 'heat exchanger 32.Conduit 36 is also connected to the upper end of standpipe |4 so as notto form a gas trap. The other end of the inner passage 35 is connectedby a conduit 31'to the 5 upper part of absorber 2|.

The lower part of absorber 2| is connected by a conduit 38 to one end ofmiddle passage 34 of heat exchanger 32. The other end of middle passage34 is connected by a conduit 39 10 to the lower part of a vessel 40. Thelower part of vessel 40 is connected by a conduit 4| to generatorchamber |3.

The upper end of generator standpipe I4 is connected by a conduit 42 toone end of out- 15 side passage 33 of heat exchanger 32. The other endof passage 33 is connected by a conduit 43 to the upper end of condenser23. The upper part of vessel 4|! is connected by a conduit 44 to conduit42. 4

The lower end of outside passage 33 is connected by a'conduit 45 to thelower part of a vessel 45. The upper part of vessel 46 is con-.

nected by a conduit 41 to the upper end of generator standpipe |5.Vessel 4G is connected 25 to the upper part of vessel 40 by athermosyphon or vapor liquid lift conduit 48'. The lower end of conduit48 projects downward into vessel 46.

The system contains refrigerant fluid, liquid 30 absorbent, andauxiliary inert fluid. These fluids may be ammonia, water, and hydrogen,respectively. Other suitable fluids may be used.

In operation, the generator II is heated by the gas burner |3. Theburner may be controlled 5 by a thermostat, not shown, responsive totem-- perature aflected by the evaporator 25. Other suitable heatingmeans may be used, such as an electric heating element or liquid fuelburner. Ammonia vapor is expelled from solution in o chambers H I2 andI3 of the generator ID by heat from the burner J9. Vapor expelled inchamber rises through standpipe H to the upper end thereof and thenenters conduit 42. Vapor expelled in chamber l2 accumulates in 45 domel6 and rises through conduit ll causing upward flow of liquid fromchamber |2 into the upper part of standpipe |4. Vapor issuing from theupper end of conduit in standpipe l4 also enters conduit 42. Liquidremoved from chamber I. I2 is replaced through opening II from chamber|3. Vapor. expelled from solution in chamber |3 rises through liquidinto the upper part of standpipe II. This vapor flowsfrom the upper partof standpipe l5 through conduit 41 2 into vessel 46. Vapor rises fromvessel 46 through conduit 48 into the upper part of vessel 40,

causing upward flow of liquid from vessel 46 into vessel 40. Vapor flowsfrom vessel 4|] through conduit 44 into conduit 42. Flow of liquidthrough the generator I 0 is from chamber 3 to chamber l2 and thenceinto standpipe I4 and chamber Concentration of ammonia in solution isless in chamber l, greater in chamber I2, and greatest in chamber I3.The temperatures of these chambers increases in the reverse order.

Liquid flows from the weak liquid chamber through conduit 36, innerpassage of heat exchanger 32, and conduit 31 into the upper part ofabsorber 2|. Liquid flows downward in the absorber. Liquid flows fromthe lower part of absorber 2| through conduit 38, middle passage 34 ofheat exchanger 32; conduit 39, vessel 40, and conduit 4| into chamberI3. The described flow of liquid from the generator to the absorber iscaused by overflow from the upper end of conduit 31 into the absorber.The described fiow of liquid from the absorber to the generator iscaused by upward flow of liquid from a lower level in the absorber to ahigher level in the generator through conduit I! by thermosyphon orvapor liquid lift action.

Vapor expelled by heat in the generator as previously described flowsfrom conduit 42 through the outside passage 33 of heat exchanger 32, andconduit 43 to the upper end of condenser 23. '23 and the liquid flowsfrom the condenser Vapor condenses to liquid in condenser ferred to aspoor and rich gas.

surface levels of liquid in the generator-absorber In the heat exchanger32, heat is transferred from weak solution flowing through centerpassage 35 to rich solution flowing in the opposite direction throughthe middle passage 34. Heat is also transferred from vapor flowing inoutside passage 33 to rich solution flowing in the-op posite directionthrough the middle passage 34. Heat transfer from vapor in the outsidepassage 33 is accompanied by condensation of water vapor. This isreferred to asrectification.

The heat exchanger 32 is located; below the vessel 40 are substantiallythe same.

liquid circuit. Condensate must therefore be removed from outsidepassage 33 to permit the flow of vapor therethrough and returned to theliquid circuit. ,The condensate drains from the lower end of outsidepassage 33 into conduit and vessel 46. The liquid is raised from vessel46 through conduit 48 into vessel 40 by upward flow of vapor throughconduit 48 as previously described. In vessel 40 the condensate joinsrich solution returning to the generator.

The surface levels of liquid in absorber 2| and The surface level ofliquid in generator standpipe I5 is lower than these levels by an amountequal to the head of liquid required for flowing the gas through liquidin vessel 46 into lower end of conduit 48. This level difference issubstantially equal to the level of liquid in the left hand end ofconduit 45 above the level of liquid in vessel 46.

Various modifications and changes may be made within the scope of theinvention as set forth in the following claims.

What is claimed is:

1. An absorption refrigeration system including an absorber, a pluralityof enclosures in which fluid therein is heated, members for circulationof absorption liquid" through said obsorber and enclosures in seriesrespectively, a second one of said enclosures and said memberscooperating to cause said liquid circulation by thermosyphon or vaporlift action, means to conduct vapor from any or all of said enclosuresin thermal exchange relation out of physical contact with absorptionliquid flowing from said absorber toward said enclosures and below thesurface level of liquid in said absorber, and means to elevatecondensate from said vapor by vapor liquid flowing from said absorber.toward said enclosures.

3. An absorption refrigeration system includ ing a generator, anabsorber," a thermosyphon.

or vapor 'lift for circulating absorption "liquid between said generatorand absorber,a conduit"; for vapor from said generator cooled by. absorpf tion liquid but of physical contactwithjthevapor and flowing towardsaid generator; f nieans'jfor syphon 'or vapor. lift, and a 'secondvaporutilizing vapor expelled by sa d heatiri vate condensate fromsaid'conduit."

4. A system as in claim 3 also having in to join elevatedcondensate'fflwith absorpt liquid flowing toward said "generator. f

s. A as heating absorption. liquid flowing to; said ther'mo1-- 5

